The fact that it was a graduation requirement and you received income does not affect the taxability of the income. Since you were paid for your work, it is taxable income.
The taxability of the income is affected by how the person paying you treated you, whether it was as an employee or as a subcontractor. Since they sent you a 1099-NEC, it seems they chose to treat you as a subcontractor. This means you would be subject to SE taxes . If you should have been an employee instead, then you would select income should have been reported on a W2.
Independent contractor (self-employed) or employee?